clearly 16 has issues with booze, but calling him an alcoholic is probably premature.

He likely fits into the alcohol abuser category and not alcohol dependent
Obviously, no one can tell without knowing him, but I think it's safe to say that 16 can go two directions from this point; take a step back and get things under control, or keep hitting the sauce.16, the reason why I quit drinking hard liquor was because about once a year, I'd wake up and not remember the last part of the night. I'd ask my friends, and every time, they'd tell me that I was a ball and had nothing to worry about. I don't like not being in control, so I quit drinking hard liquor. Thing is, I'm not an alcoholic. Growing up in an Irish family, booze have been and always will be around, so yeah, I was worried for a long time. I've settled in the older I get and the micros are a good for me. The older I get, the less I drink.
It seems like you have a good family/friend structure so listen to them. If they have the concerned look, or if they tell you that 16 is not the 16 we know when you drink, then fix things. Getting sloshed a few times is not a sign of an alcoholic if you recognize it and make adjustments. My Grandma (dead, thank God... horrible woman), Uncle (dead also, and did things that are unmentionable), and cousin were all alcoholics. In my experience, an alcoholic can't drink and be responsible, period. Thank God that my cousin finally realized that. I have no clue if you're an alcoholic.
Take a step back man. As a kid, you had to have hobbies, activities, etc. that you enjoyed. Start working those back into your life and go from there.
Sorry for the soap box. And to be clear, I'm drinking a beer right now.